[SOLVED]Refresh Rate Problem

jcjefferies · February 23, 2017 at 3:10 PM

Is it possible to add or force a 50HZ refresh rate when not listed under Settings > System > Display?

I have an Intel Celeron and a AMD E450 Nettop PCs and with any version of LibreElec including 8.0 both only offer the refresh rates 23.98Hz, 24Hz & 30Hz at 1080p resolution when connected to my Sharp TV. The same PCs offer the full range of refresh rate up to 60 Hz when connected to other TVs at 1080p

If I install Windows on the same PCs connected to the Sharp TV the full range of refresh rates are on offer up to 60 HZ at 1080p.

If I install Linux (Ubuntu) on one of the PCs I am only offered 23.98Hz, 24Hz & 30Hz at 1080p resolution so looks like a Linux problem!

However my RPi2 running any version of LibreElec connected to the Sharp TV at 1080p, 50Hz refresh is one of options.

Chris

vitorp07 · February 23, 2017 at 4:56 PM

First what is the TV model and how is it connected, HDMI?
With the TV powered on and connected to your PC, can you SSH and copy/paste the output of the following command

Code

xrandr

jcjefferies · February 23, 2017 at 5:26 PM

TV is Sharp LC-40sh340K

HDMI connection. Both HDMI behave the same

libreelec:~ # xrandr
Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 32767 x 32767
DP1 disconnected primary (normal left inverted right x axis y axis)
DP2 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
HDMI2 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 890mm x 500mm
1920x1080i 60.00*+ 50.00 59.94
1920x1080 24.00 23.98
1280x720 60.00 50.00 59.94
1440x480i 59.94
720x576 50.00
720x576i 50.00
720x480 60.00 59.94
720x480i 60.00 59.94
640x480 60.00 59.94
VGA1 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)
libreelec:~ #

Thanks Chris

vitorp07 · February 23, 2017 at 5:39 PM

EDIT: on your TV's manual it says the HDMI connector supports 1080i only not 1080p so if that is correct(could be a typo) if you select 1080p in Kodi Display settings this is probably why you only get to choose 30Hz

SSH and try this below. (where "50.00" is you could put "60.00" if you want)

Code

xrandr --output HDMI2 --mode 1920x1080 --rate 50.00

If it does work properly SSH again and do these command below, be sure not to change the HDMI port used "HDMI2".

Code

echo "#!/bin/sh" > /storage/.config/autostart.sh

Code

echo "xrandr --output HDMI2 --mode 1920x1080 --rate 50.00" >> /storage/.config/autostart.sh

jcjefferies · February 24, 2017 at 3:53 PM

Thanks! Unfortunately all the command does is remove the 1080p x 30Hz option in Kodi!

Checking the TV manual the HDMI connections are supposed to support 1080p at 24Hz, 50Hz & 60Hz.

The TV displays the resolution for about 1/2 second and the RPi2 running LibreElec 8.0 is definitely running at 1080p x 50Hz as set in Kodi.

I now have memories of using xrandr and cvt to define a resolution a year or two ago. All I can think is that before I discovered OpenElec I was using Kodi on Ubuntu and had this same problem on the two nettop clients. Unfortunately neither cvt or gtf seem to work on LibreElec to produce the modeline.

For comparison this is output when my old original Kodi Pentium4/Nvidia 210 Video client is connected to the same TV which runs at 1080p x 50Hz.

LibreELEC (official) Version: 7.0.2()
LibreELEC6:~ # xrandr
Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 8192 x 8192
DVI-I-0 disconnected primary (normal left inverted right x axis y axis)
VGA-0 disconnected (normal left inverted right x axis y axis)
DVI-I-1 disconnected (normal left inverted right x axis y axis)
HDMI-0 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 890mm x 500mm
1920x1080 60.05 + 59.94 50.00* 23.97 60.00 50.04
1440x480 60.05
1280x720 60.00 59.94 50.00
720x576 50.00 50.08
720x480 59.94 60.05
640x480 59.94 59.93
LibreELEC6:~ #

I have only just noticed that my satellite set top box connected to the other HDMI connection runs at 1080i but there is no option to change this in the box setup. The simple work around seems to be to resort to 1080i x 25 Hz as I cannot detect any problems with the picture and the TV detects it as 1080i x 50Hz.

Thanks for the help

Chris

jcjefferies · February 25, 2017 at 9:25 PM

The link below solved my problem!!

Configuring a Custom xorg.conf - OpenELEC

Create a txt file called "xorg.conf" in ./config or from Windows in "configfiles" with the contents or the appropriate Intel, Nvidia or AMD file.

After reboot I now have 50Hz and 60Hz refresh added to 1080p options so I dont have to use 1080i x 25 Hz and can now use 1080p x 50Hz

Chris

[SOLVED]Refresh Rate Problem

Similar Threads

cubox-i4pro LE 8.0.1 refresh rate switching

Refresh rate problem after update from Openelec